Attention-deficit hyperactivity disorder (ADHD) can have a considerable impact on the day-to-day functioning and overall wellbeing of people affected. It causes a variety of symptoms including difficulty focusing, impulsivity and hyperactivity.

For many, a diagnosis of ADHD, whether in childhood or adulthood, is life changing. It means finally having an explanation for these challenges, and opens up the opportunity for treatment, including medication.

Although ADHD medications can cause side effects, they generally improve symptoms for people with the disorder, and thereby can significantly boost quality of life.

Now a new study has found being treated for ADHD with medication reduces the risk of early death for people with the disorder. But what can we make of these findings?

A large study from Sweden

The study, published this week in JAMA (the prestigious journal of the American Medical Association), was a large cohort study of 148,578 people diagnosed with ADHD in Sweden. It included both adults and children.

In a cohort study, a group of people who share a common characteristic (in this case a diagnosis of ADHD) are followed over time to see how many develop a particular health outcome of interest (in this case the outcome was death).

For this study the researchers calculated the mortality rate over a two-year follow up period for those whose ADHD was treated with medication (a group of around 84,000 people) alongside those whose ADHD was not treated with medication (around 64,000 people). The team then determined if there were any differences between the two groups.

What did the results show?

The study found people who were diagnosed and treated for ADHD had a 19% reduced risk of death from any cause over the two years they were tracked, compared with those who were diagnosed but not treated.

In understanding this result, it’s important – and interesting – to look at the causes of death. The authors separately analysed deaths due to natural causes (physical medical conditions) and deaths due to unnatural causes (for example, unintentional injuries, suicide, or accidental poisonings).

The key result is that while no significant difference was seen between the two groups when examining natural causes of death, the authors found a significant difference for deaths due to unnatural causes.

So what’s going on?

Previous studies have suggested ADHD is associated with an increased risk of premature death from unnatural causes, such as injury and poisoning.

On a related note, earlier studies have also suggested taking ADHD medicines may reduce premature deaths. So while this is not the first study to suggest this association, the authors note previous studies addressing this link have generated mixed results and have had significant limitations.

In this new study, the authors suggest the reduction in deaths from unnatural causes could be because taking medication alleviates some of the ADHD symptoms responsible for poor outcomes – for example, improving impulse control and decision-making. They note this could reduce fatal accidents.

The authors cite a number of studies that support this hypothesis, including research showing ADHD medications may prevent the onset of mood, anxiety and substance use disorders, and lower the risk of accidents and criminality. All this could reasonably be expected to lower the rate of unnatural deaths.

Strengths and limitations

Scandinavian countries have well-maintained national registries that collect information on various aspects of citizens’ lives, including their health. This allows researchers to conduct excellent population-based studies.

Along with its robust study design and high-quality data, another strength of this study is its size. The large number of participants – almost 150,000 – gives us confidence the findings were not due to chance.

The fact this study examined both children and adults is another strength. Previous research relating to ADHD has often focused primarily on children.

One of the important limitations of this study acknowledged by the authors is that it was observational. Observational studies are where the researchers observe and analyse naturally occurring phenomena without intervening in the lives of the study participants (unlike randomised controlled trials).

The limitation in all observational research is the issue of confounding. This means we cannot be completely sure the differences between the two groups observed were not either partially or entirely due to some other factor apart from taking medication.

Specifically, it’s possible lifestyle factors or other ADHD treatments such as psychological counselling or social support may have influenced the mortality rates in the groups studied.

Another possible limitation is the relatively short follow-up period. What the results would show if participants were followed up for longer is an interesting question, and could be addressed in future research.

What are the implications?

Despite some limitations, this study adds to the evidence that diagnosis and treatment for ADHD can make a profound difference to people’s lives. As well as alleviating symptoms of the disorder, this study supports the idea ADHD medication reduces the risk of premature death.

Ultimately, this highlights the importance of diagnosing ADHD early so the appropriate treatment can be given. It also contributes to the body of evidence indicating the need to improve access to mental health care and support more broadly.

Hassan Vally, Associate Professor, Epidemiology, Deakin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It’s cold and wet outside. As you get out of bed, you can feel it in your bones. Your right knee is flaring up again. That’ll make it harder for you to walk the dog or go to the gym. You think it must be because of the weather.

It’s a common idea, but a myth.

When we looked at the evidence, we found no direct link between most common aches and pains and the weather. In the first study of its kind, we found no direct link between the temperature or humidity with most joint or muscle aches and pains.

So why are so many of us convinced the weather’s to blame? Here’s what we think is really going on.

Weather can be linked to your health

The weather is often associated with the risk of new and ongoing health conditions. For example, cold temperatures may worsen asthma symptoms. Hot temperatures increase the risk of heart problems, such as arrhythmia (irregular heartbeat), cardiac arrest and coronary heart disease.

Many people are also convinced the weather is linked to their aches and pains. For example, two in every three people with knee, hip or hand osteoarthritis say cold temperatures trigger their symptoms.

Musculoskeletal conditions affect more than seven million Australians. So we set out to find out whether weather is really the culprit behind winter flare-ups.

What we did

Very few studies have been specifically and appropriately designed to look for any direct link between weather changes and joint or muscle pain. And ours is the first to evaluate data from these particular studies.

We looked at data from more than 15,000 people from around the world. Together, these people reported more than 28,000 episodes of pain, mostly back pain, knee or hip osteoarthritis. People with rheumatoid arthritis and gout were also included.

We then compared the frequency of those pain reports between different types of weather: hot or cold, humid or dry, rainy, windy, as well as some combinations (for example, hot and humid versus cold and dry).

What we found

We found changes in air temperature, humidity, air pressure and rainfall do not increase the risk of knee, hip or lower back pain symptoms and are not associated with people seeking care for a new episode of arthritis.

The results of this study suggest we do not experience joint or muscle pain flare-ups as a result of changes in the weather, and a cold day will not increase our risk of having knee or back pain.

In order words, there is no direct link between the weather and back, knee or hip pain, nor will it give you arthritis.

It is important to note, though, that very cold air temperatures (under 10°C) were rarely studied so we cannot make conclusions about worsening symptoms in more extreme changes in the weather.

The only exception to our findings was for gout, an inflammatory type of arthritis that can come and go. Here, pain increased in warmer, dry conditions.

Gout has a very different underlying biological mechanism to back pain or knee and hip osteoarthritis, which may explain our results. The combination of warm and dry weather may lead to increased dehydration and consequently increased concentration of uric acid in the blood, and deposition of uric acid crystals in the joint in people with gout, resulting in a flare-up.

Why do people blame the weather?

The weather can influence other factors and behaviours that consequently shape how we perceive and manage pain.

For example, some people may change their physical activity routine during winter, choosing the couch over the gym. And we know prolonged sitting, for instance, is directly linked to worse back pain. Others may change their sleep routine or sleep less well when it is either too cold or too warm. Once again, a bad night’s sleep can trigger your back and knee pain.

Likewise, changes in mood, often experienced in cold weather, trigger increases in both back and knee pain.

So these changes in behaviour over winter may contribute to more aches and pains, and not the weather itself.

Believing our pain will feel worse in winter (even if this is not the case) may also make us feel worse in winter. This is known as the nocebo effect.

What to do about winter aches and pains?

It’s best to focus on risk factors for pain you can control and modify, rather than ones you can’t (such as the weather).

You can:

• become more physically active. This winter, and throughout the year, aim to walk more, or talk to your health-care provider about gentle exercises you can safely do at home, with a physiotherapist, personal trainer or at the pool
• lose weight if obese or overweight, as this is linked to lower levels of joint pain and better physical function
• keep your body warm in winter if you feel some muscle tension in uncomfortably cold conditions. Also ensure your bedroom is nice and warm as we tend to sleep less well in cold rooms
• maintain a healthy diet and avoid smoking or drinking high levels of alcohol. These are among key lifestyle recommendations to better manage many types of arthritis and musculoskeletal conditions. For people with back pain, for example, a healthy lifestyle is linked with higher levels of physical function.

Manuela Ferreira, Professor of Musculoskeletal Health, Head of Musculoskeletal Program, George Institute for Global Health and Leticia Deveza, Rheumatologist and Research Fellow, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.